If you know you met this player once before but can't remember if s/he was good or bad... Karma is for you.

Karma allows you to track where you hung around with other people, what quests you completed (or just made progress) with them, and you can add notes for specific information worth remembering (the good, the bad and the ugly...)
And the Karma value is for your overall impression, how much you liked grouping with them. (E.g. you can sort the list of people you met by the Karma value, so the "nicer" people are listed first.)

It adds a minimap button which you can left-click to open the main window, middle-click to open the new LFM window. (You can also configure a key mapping for that in the normal keyboard configuration of WoW. Personally, I use shift-K/shift-L.)

It also got some LDB support in version 30102.D (but I never tried it on large raids to see if the tooltip is not too large - your mileage may vary).

(KarmaTrans is a helper AddOn to store extra stuff. You don't need to enable it usually.)

(TODO: transfer some of the Changelog data that was only stored with the Cata beta version)

20101202 (v40003.01): >>
New:
- added gearscan:
- does NOT store the whole gear, only a general figure
- sums the item level of all slots, modified by item quality and slot importance
- only shows atm in the tooltip of the Karma window (TODO: show in tooltip extension to mouse-over/target/unitframe)

Changed:
- moved 3.x changelog into Changelog-pre-4.0.txt
- tooltip: if most-recently-joined-with-char is the current char, don't show twice
- talent scan: mentioning successful scan now in secondary window
- achievements:
- dropped the old, dead categories from LK (with compatibility code for 3.x clients to put them back in)
- added code to only test the achievements matching the current raid size
(this is likely not compatible with languages using non-Arabic number symbols,
as the title of the achievement is scanned for 10/25; don't know though which
WoW languages would have an issue here, feedback welcome)

20110424 (v40003.02 / v40100.01pre):
- DK: tank tree is blood, not frost any longer... (should've released that change since months :D)
- 4.1.x compatibility code to not trip over Blizzard's newest nasty land mine for older addons (COMBAT_LOG_EVENT_UNFILTERED change)
- gear 'score':
- using simple ilvl as in the default UI
- added option to show/hide gear level in tooltip
- dungeon tracking:
- changed display to two lines (dungeon entered / left)
- storing role in group in random dungeon groups
- ignore list: added mouse-over tooltip for players on ignore with a Karma note (for reasons unfathomable, you can add notes to friends but not to ignored people in the default UI)
- cutthroat "achievement": not tracking for players below level 80
- LFM module: added fancy down-arrows above the right table to clearer indicate the on-top descriptions of the columns

20110428 (missing entry)

20110505 (v40100.01):
- mouseover the player unit shows the equipped ilvl
- fixed an error in ilvl calculation: main hand 2H weapon was accounted wrong
- friendlist: now shows class/level/seen for known offline players
- friendlist: fixed an unnecessary potential taint by always hooking the mouseover
- fixed an error in merging a char with an empty comment back from history

Updated to not barf on 5.4.
Also made it tolerate that monks start as neutral. (That's sort of work in progress though, because I need to recheck those pieces of code which rely on there being exactly two factions.)

Hello.
I love this addon that I use for many years. Unfortunately, since the 4.0.1 patch, it no longer works. The people in the group are no longer automatically added to Karma. They are white.
I have this error when loading my character: